Statistical-Mechanical Description of Nonequilibrium Processes in Interacting Lattice Gases

Abstract

The nonequilibrium statistical ensemble method due to D. Zubarev is used to develop a theory of nonequilibrium processes (diffusion, thermal diffusion, heat conduction, structural relaxation) in interacting lattice gases. Deviations of particle and energy densities from their equilibrium values obey a system of Langevin-type equations that allow one to deduce microscopic expressions for different transport coefficients. All the expressions consist of two parts, one is proportional to a static correlation function and the other to the time integral of a time correlation function. The latter describes specific statistical memory effects, which are important, for example, in highly ordered states. In many cases, however, these memory effects can be disregarded. Then the transport coefficients are represented by the chemical diffusion coefficient at a zero concentration limit and equilibrium lattice gas characteristics, namely, its chemical potential, lattice concentration, temperature, and distribution functions, which are calculated within the selfconsistent diagram approximation.